Applicants claim priority under 35 U.S.C. xc2xa7119 of GERMAN Application No. 299 09 542.8 filed Jun. 1, 1999. Applicants also claim priority under 35 U.S.C. xc2xa7120 of PCT/DE00/01723 filed on May 25, 2000. The international application under PCT article 21 (2) was not published in English.
1. Field of the Invention
The present invention is concerned with a filler valve assembly to fill packing pouches or flat bags with inhomogeneous substantially liquid or pasty products.
2. Description of the State of Art
Filler valve assemblies of this type, basically, comprise a valve head including a central discharge outlet to be opened and closed by a plunger adjustable within the valve head and being in communication with the means for supplying the fill products.
A filler valve assembly of the afore-described type has been disclosed, for example, by U.S. Pat. No. 5,822,958, used to discharge the viscous products containing xe2x80x9cparticulate matterxe2x80x9d, i.e. small solid particles. The valve head is substantially formed of a hollow casing, the cavity of which, at the bottom end, passes over into a short discharge outlet in which a plunger reciprocates whose the plunger rod is guided within the cavity. The supply of the inherently inhomogeneous product to the discharge outlet takes place from the cavity to which the fill product is fed through a tube connected to the valve head, with the plunger rod also extending within the said tube. During dispensing, it is not safeguarded that each lot discharged into a bag has the same mixing ratio of the solid particles and the viscous component because, as stated previously, the fill product supply exclusively takes place through the cavity, i.e. in the event that a segregation has previously taken place in the fill product (always to be reckoned with) it is no longer safeguarded that each of the filled bags and each of the individual lot dispensed is of the same mixing ratio within the fill product. Moreover, the cross-sectional shape of the valve head according to U.S. Pat. No. 5,822,958 is relatively unfavourable for loading flat bags, as the cross-section thereof in flared condition substantially corresponds to a bi-angle.
It is an object of the invention to improve a fill valve assembly of the afore-described part to the effect that a substantially constant mixing ratio of at least two parts of the fill product be safeguarded in each lot of the fill product discharged by the valve into a bag.
Another object of the invention resides in better adapting the fill valve assembly and the valve head, respectively, to filling flat bags, and, finally, it is another object of the invention to enable easier purging of the fill valve assembly.
To achieve the afore-described objects, in the practice of the invention, a fill valve assembly is provided wherein, in combination, the valve head, in cross-section, is in the form of a flat rhombus or ellipse defined by a primary and by a substantially smaller secondary axis, and wherein the discharge outlet adjusted to the plunger diameter is extended into the valve head and is so dimensioned that it corresponds to at least twice the length of the plunger, with the extended portion of the said outlet accommodating the plunger in the open position thereof, and that provided on both sides of and in side by-side relationship with the extended discharge outlet, on the major axis of the rhombic cross-section, within the valve head, is at least respectively one product supply passage terminating in the bottom part of the discharge outlet.
As opposed to the fill valve assembly according to U.S. Pat. No. 5,82,958, showing a cavity from which the fill product simply flows off when the discharge outlet is in its open position, the plunger mounting and product supply spaces are separate, with the latter being in the form of at least two separate product supply passageways, thereby enabling the fill product components to be united separately and exactly metered directly ahead of the actual valve outlet, thus safeguarding that each of the dispensed lot is of the same mixing ratio. Moreover, the cross-sectional shape of the valve head adjusted, in the practice of the invention, to the flat bag shape, is used to directly accommodate the separate product supply passageways within the valve head.
To satisfy in valves of this type, the inevitable purging requirements (e.g. in product changes) and to comply with mandatory statutory sanitary provisions, in the practice of the invention, an advantageous development resides in that the upper end portion of the extended outlet passageway be of a diameter slightly larger than the plunger diameter and be provided with plunger guiding bridges. The said extended end portion is designed to serve as a detergent supply space provided with a detergent supply nozzle.
As described hereinafter in closer detail, it will also be possible for the detergent to be supplied through the plunger rod. It is true, a hollow plunger rod of this type along with a corresponding bore in the plunger, is also provided with the valve assembly according to the afore-quoted U.S. Pat. No. 5,822,958; however, in that citation, it serves to blow suitable gases therethrough to help to clear the outlet opening of the cavity in case it should have become stuck.